Ironman is an optional game mode that restricts the player's control over their save file, effectively removing the ability to correct mistakes or change decisions made during the course of play. Ironman can be enabled from the settings screen when starting a new campaign.
Steam achievements can only be unlocked with ironman enabled.
Ironman has a number of restrictions:
- The checksum must be the same as one of the official releases. Any mod that changes it (broadly, this means one that affects gameplay) will cause ironman mode to be disabled.
- Only a single save will be stored; it is thus impossible to load an earlier save if something goes wrong (unfortunately, this includes save game corruption).
- The game saves automatically whenever almost any decision is taken (such as declaring war).
- Save files can be stored in the Steam cloud or on a local drive, but are encrypted and cannot be edited.
Save file storage
There are two options for save locations for Ironman mode. Local Ironman saves are always uncompressed and are stored in:
Documents\Paradox Interactive\Hearts of Iron IV\
- (for Mac)
~/Documents/Paradox Interactive/Hearts of Iron IV/save games/
- (for Linux)
~/.local/share/Paradox Interactive/Hearts of Iron IV/save games/
If cloud saving is enabled, the save will be always compressed and uploaded to the Steam servers. A backup is also kept locally on your computer, at:
C:\Program Files (x86)\Steam\userdata\<YOUR STEAM ID>\394360\remote\save games// needs updating number
For Mac user is at:
~/Library/Application Support/Steam/userdata/<YOUR STEAM ID>/394360/remote/save games//needs updating number
On GNU/Linux they are stored in:
~/.steam/steam/userdata/<YOUR STEAM ID>/394360/remote/save\ games/
The "Steam Cloud" option must be enabled for the game in the Steam library (Hearts of Iron IV/Properties/Updates). This also requires that "Enable Steam Cloud synchronization for applications which support it" is enabled in the Steam settings (Steam/Settings/Cloud).